30 April, 2012

Zoology (pronounced zo-ology; the first syllable rhymes with "toe") is the study of animals and their biology, including physiology, development, and classification.

Aristotle was one of the first to classify life, at around 400 BCE. He separated plants from animals, red-blooded creatures from those who didn't have red blood, animals that walked from those that flew, etc., etc. Now animals are classified much more specifically into Kingdoms, Phyla, Classes, Orders, Families, Genera, and Species. Charles Darwin was another influential figure in the field of zoology; his theory of evolution crystallized the relationship between animals, including (perhaps especially) humans.

It is a very wide field encompassing many other disciplines, such as those focused on specific animals, a few examples of which would be arcinology (crustaceans), cetology (whales), lepidopterology (butterflies), ornithology (birds), and zoophytology (zoophytes, or animals that appear to be plants). The International Society of Zoological Sciences recognizes 17 sub-fields. Zoology can be an applied science, meaning that research is sometimes conducted for a specific purpose, rather than just for its own sake.

E. O. Wilson is a Research Professor Emeritus at Harvard University, who obtained a B.S. and M.S. in Biology from the University of Alabama and a Ph.D. from Harvard and has been on the Harvard faculty since 1956. He developed the theory of biogeography, or that the immigration and extinction of species (and therefore their biodiversity) on islands is related to the distance those islands are from the original source of the species. He also coined the word biophilia--love of life--in his book Biophilia, which had a great impact on conservation, and in his book Sociobiology: The New Synthesis, he connected animal and human behavior, sparking much controversy.

He has been awarded the Pulitzer Prize twice for his books On Human Nature and The Ants written with Bert Holldobler, the National Medal of Science, Japan's International Prize for Biology, and Sweden's highest award for non-citizens of Commander, First Class, Royal Order of the Polar Star, among others. He was chosen as one of Time magazine's 25 Most Influential Americans in 1995.

Video of E. O. Wilson explaining biogeography:

**********

And because zoology is all about animals (plus, it's the last day of the A-Z Challenge and you all deserve a break from the scientific facts I've been bombarding you with for the last month) I thought I'd give you something to look at from Wikimedia Commons's Featured Pictures, in no particular order:

28 April, 2012

To partly continue yesterday's post about the X chromosome (though reading that one isn't absolutely necessary, in case you're wondering), the Y chromosome, unlike the X chromosome, is associated with males, since males are XY and females are XX. The Y chromosome has around 58 million DNA base pairs (opposed to the X's 155 million), 70-200 genes, and makes up about 2% of all DNA.

95% of the Y chromosome is male-specific, although sections called the pseudoautosomal regions have identical counterparts on the X chromosome. Because of this, only pseudoautosomal regions can exchange places in a process called recombination (which occurs between all of the two X chromosomes in females) and male offspring possess an almost identical copy of their father's Y chromosome.

Conditions that can result from changes in the Y chromosome include 48,XXYY syndrome (where there is both an extra X and an extra Y chromosome in males) and 47,XYY syndrome (where there is the normal one X chromosome, but two Y chromosomes).

A graphic example of 47,XYY syndrome, with a male on the left
and female on the right, by Silver Spoon and Lucas Zienius,
CC-BY-SA-3.0. SOURCE.

As I was researching this post, I also found that there was a good deal (as in, webpage after webpage) of speculation that men would start to die out, since the Y chromosome shrank from being identical in size to the X chromosome to its current state of having fewer than 10% of the number of genes on the X.

However, this is theory has been rather debunked by the finding that no Y chromosome genes have been lost for six million years, and that the Y chromosome evolves rapidly. So, it seems half of the human race is genetically safe. (The chances that humanity will survive for another six million years might be far off, anyway.)

I hope I've made this part of chromosomal biology interesting for you all. Though if not, I hope you'll come back on Monday anyway in which I address a topic that's easier and allows for some great (in my opinion, at least) photographs. ;)

And since it's the second-to-last day of the Challenge: Are you looking forward to slowing down on the blogging in May, or will you just miss it? I'm a bit of both . . .

27 April, 2012

The X chromosome is one of two human sex-linked chromosomes, the other being the Y chromosome.

The X chromosome has around 155 million DNA base pairs, or 1000-2000 genes. 1,098 of those genes code for proteins and consist of around 5% of all the DNA in human cells. The X chromosome is larger and carries more genes than the Y chromosome, which means that if a gene on the X chromosome codes for a disease, that recessive trait will apear in any male children, since there is no dominate gene to counteract it. This characteristic of the X chromosome is visible in the fact only female cats can be calico, for its the females carry the allele for color and it can only code for one color at a time.

Females get two X chromosomes and males an X and a Y; since the normal chromosome count is 46 in total, females are denoted as 46,XX and males 46XY. In all cells other than egg cells, one of the two X chromosomes is inactivated (called Lyonization) except for a small area called the pseudoautosomal region. Many of the genes in the pseudoautosomal region are necessary for human development.

A graphic of triple X syndrome, with a male on the left and female on the right, by Silver Spoon, CC-BY-SA-3.0. SOURCE.

Problems that can arise from changes along the X chromosome include microphthalmia (deletion of some of the genetic information on the chromosome; results in failure to create the enzyme holocytochrome c-type synthase, which in turn produces cytochrome-c, which in turn is involved in oxidative phosphorylation that allows mitochondria to create ATP), triple X syndrome (also known as 47,XXX and trisomy X; caused by having three X chromsomes), and Turner syndrome (also called 45,X, it is when only one normal X chromsome is present and the second of the pair is missing or changed; occasionally, only some cells are altered, called mosaicism).

A video about genetics, which explains the role of chromosomes and DNA:

And if you want information about the other chromosome, stop by tomorrow--I also explain why there was speculation humanity would go extinct because of the Y chromosome. Just in case that interests you . . .

26 April, 2012

Wave-particle duality is a principle of quantum physics that says matter and light act as both waves and particles, and that the observed behavior depends on the experiment.

Since the 1600s, scientists tried to figure out whether light, a type of electromagnetic radiation, came in waves or was made up of particles. Christiaan Huygens developed a wave theory (also suggesting that there was a luminiferous ether through which waves traveled, since it was generally thought waves needed a medium) and Isaac Newton a particle (or corpuscular) theory. It wasn't until the 1800s with Thomas Young's double-slit experiment and the buildup of other evidence pointing toward the fact light acted like a wave that Newton's theory was overturned. At least until the Michelson-Morley Experiment, which tried and failed to find any ether.

There are six major types of light phenomenon: reflection, refraction, interference, diffraction, polarization, and the photoelectric effect, all of which can be explained by wave theory, except for the photoelectric effect. Then Albert Einstein published a paper that explained it (introducing photons as continuous waves in 1905), wave-particle duality was also proved to take place with matter by Louis de Broglie (who was awarded the Novel Prize in 1929), and Niels Bohr proposed that light could take on either wave or particle characteristics. Hence, with no other explanation, duality was accepted as reality.

One of the more famous experiments done which helped prove wave-particle duality was Young's Double Slit Experiment. To take Richard Feynman's analogy, imagine someone shooting at a wall through two slits in a sheet of metal. You would expect the bullets to be centered close to two narrow bands on the far wall--but with light, that isn't true. Instead (to stretch the example a bit far) the pattern of bullets would show up as an interference pattern (bright and dark bands, in the case of light; see above image) as though projectiles were passing through the slits at the same time and bouncing off each other.

No notable scientist today. Quantum physics is far from stagnant, of course, but I don't know of any wave-particle dualicists. But if you'd like a simulated ripple tank to play around with that has an example of the double-slit experiment (just make sure you have Java):

25 April, 2012

The field examines the formation and classification of volcanoes, matter expelled during eruptions (pyroclastic flows, lava, dust, ash, gases), volcanic relations to other geologic events (mountain building, earthquakes), and attempts to predict when volcanoes may erupt. It also involves geophysics, geochemistry, seismology, and geodesy.

Volcanoes form because of rising magma from beneath the surface of Earth, usually close to the edges of tectonic plates. There are three types of volcanic activity: spreading center volcanism (takes place along diverging plates), subduction zone volcanism (takes place where two plates converge) and intraplate volcanism (takes place mid-plate where there are no plate edges).

Volcano types are further classified as cones (steeply sloped with the typical volcano shape), shield volcanoes (shallow sloped), and stratovolcanoes (also known as composite volcanoes; they are shallow at the base, curves sharply upward toward the top). Some major kinds of eruptions include fissure eruptions (eruptions occur along a line), Hawaiian eruptions (relatively calm flows of basalt lava with little volcanic gas), Strombolian eruptions (explosive, noisy eruptions that involve a lot of volcanic gas), Vulcanian eruptions (short series of eruptions that send up a lot of rocks at the onset but become quieter and steadier after some time), Plinian eruptions (generate plumes of ash that travel up to 45 km into the air), and hydrovolcanic eruptions (eruptions that happen in water).

Haraldur Sigurðsson is a volcanologist and marine geologist. He received a Ph.D. in Petrology/Geochemistry from Durham University and is a current Professor of Oceanography at the University of Rhode Island. He has studied volcanoes in Iceland, North America, South America, the Caribbean, Indonesia, Italy, and Africa, and has researched underwater volcanoes. He was awarded the Coke Medal by the Geological Society of London for his work. Sigurðsson has also hosted several TV documentaries, including The Riddle of Pompeii, Horizon, Naked Science, and Timewatch.

Video with Haraldur Sigurðsson (embedding was disabled, so I couldn't put it directly in this post):

24 April, 2012

The Unified Theory of physics, also known as the Grand Unified Theory (GUT) or Theory of Everything (TOE), is a yet-to-be-found theory that would bring together the strong force, weak force, electromagnetic force, and gravity into a single theory.

The history of the search for a unified theory started with James Maxwell, who from 1861-65 demonstrated that electricity and magnetic fields were related, in his theory of electromagnetism. Then, in 1881-84, Heinreich Hertz discovered light and radio waves were also examples of electromagnetism. Albert Einstein tried for 30 years but could not find a theory that united the remaining forces.

There have been several theories proposed as solutions to GUT. One is supersymmetry (it proposes that all matter has a massive "shadow" force carrier), and another string theory (the idea there are more than three dimensions and that particles consist of strings and membranes), but there is no theory that has been broadly accepted.

And today there are three Notable scientists who have worked on unified field-related research. Three, because I was having trouble narrowing it down to one (links will take you to past A-Z Challenge posts on this blog, with the info about the scientists at the bottom):

23 April, 2012

Toxicology is the study of the effects, detection, and treatment of poisons.

The field involves chemistry, biology, pathology, pharmacology, physiology, medicine, and many other fields, and is divided into observational studies (effects of substances), mechanistic studies (explaining how the effects occur), risk assessment (the probability that exposure will cause adverse effects), regulatory toxicology (whether there's too much risk in allowing people to be exposed to a substance), clinical toxicology (tries to determine whether effects are caused by a certain chemical), and forensic toxicology (evaluation and testimony in legal situations).

There are three types of toxic substances: toxicants (anything that causes adverse biological effects), toxins (proteins created by living organisms that have immediate effects), and poisons (toxicants that cause death or illness in a short amount of time). Toxic substances can be systemic (they affect multiple organs) or limited to certain sites. Xenobiotics are substances that enter the body (from the Greek word xeno, or "foreigner").

There are four kinds of reactions: additivity reactions (two or more chemicals have the same affect as they would individually, just simultaneously), antagonism (one chemical reduces the effect of another), potentiation (a chemical causes another to become more toxic), and synergism (two chemicals multiply each other and create a greater response). Toxicokinetics is the movement of a chemical through the body, and toxicodynamics is how it interacts with the body it's in.

William Baird is a professor at the EMT and Biochemistry and Biophysics Department at Oregon State University, who received a Ph.D. from the McArdle Laboratory of Cancer Research. His research group focuses on how different chemicals can cause cancer, including the environmental pollutants polycyclic aromatic hydrocarbons (PAH). The research also includes how enzymes activate and detoxify PAH, how PAH binds to DNA (forming "adducts", or DNA bound to a carcinogen) and how the structure of chromatin (proteins and DNA in the nucleus of the cell) and DNA sequence affect how adducts form.

In the physics sense, spectra (the plural of spectrum) are energy emitted in the form of different wavelengths, such as electromagnetic radiation, which includes gamma rays, x-rays, ultraviolet, visible light, infrared, microwaves, and radio waves. Spectroscopy is used to determine the composition and the movement of matter, based on how it reacts to radiation.

Part of spectroscopy focuses on visible light and its colors, though there is also--and to name just a few of the many different kinds of spectroscopy--atomic absorption spectroscopy (the study of how energy is absorbed using radiation), electron paramagnetic spectroscopy (which uses microwaves), electron spectroscopy (measures changes in electron energy levels), Fourier transform spectroscopy (matter is bombarded with radiation and the results analyzed with mathematics), gamma-ray spectroscopy, infrared spectroscopy, mass spectrometry (generates ions that interact with the matter in question), Mossbauer spectroscopy (used in mineralogy to detect iron), Raman spectroscopy (uses the scattering of light to find the vibration and rotation of molecules), and x-ray spectroscopy.

For more detail about how spectroscopy actually works, let's take the example of light. Light spectroscopy examines continuous and discrete spectra: A continuous spectrum includes a range of colors with few interruptions along the observed wavelengths, while a discrete spectrum has dark-light contrast between wavelengths.

Specific elements can be determined using spectroscopy because when an atom absorbs energy its electrons move into a higher orbit, and when the electrons fall back to a lower orbit, energy is released in the form of a certain wavelength of radiation. With discrete spectra, brighter colors are emission spectra and
darker spikes are absorption spectra, and these fluctuations are
characteristic to certain atoms and molecules. This use of spectroscopy is particularly important in astronomy, and the matter, temperature, density, and motion of objects in space can be discerned from those observed changes.

Joseph Hornak is a Professor of Chemistry, Materials Science and Engineering, and Imaging Science at the, and the Director of the Magnetic Resonance Laboratory at the Rochester Institute of Technology (RIT), as well as an Adjunct Associate Professor of Radiology at the University of Rochester. He graduated with a Ph.D. in Chemistry from Notre Dame University and is a Fellow of the American Chemical Society, International Society of Magnetic Resonance, and the Environmental and Engineering Geophysical Society.

His research at RIT involves magnetic resonance imaging (MRI) and magnetic resonance spectroscopy.

20 April, 2012

Robotics is a branch of technology focused on the design and use of robots.

The word "robot" comes from the Czech word robota, or "forced labor", and the word "robotics" was coined by Science Fiction writer Isaac Asimov in 1941. There are five main physical elements to a robot: the structure, the power source, the sensors, the actuators (the things that make the robot move), and the controller (the "brain" of the robot). Most robots are mobile (using wheels or joints run by actuators, which can be powered by electric motors, hydraulic systems, or pneumatic systems), have an electrical circuit to which the actuators are connected, and are reprogrammable.

A common type of robot is the robotic arm, a stationary type of robot that has seven segments and six joints; they are prominent in manufacturing and require a good deal of accuracy. Robots that can move from place to place are more complicated, and require wheels, tracks, or legs, in addition to some way of properly controlling those methods of movement and compensating when out of balance. There are even more robot types when you consider remote and autonomous robots. Remote robots (or puppet robots) are controlled by people, whereas autonomous robots can control their movements on their own. They use a variety of sensors including ultrasound and infrared, and some of the fancier machines use stereo vision (which gives them depth perception).

Yoky Matsuoka is an Assistant Professor at the Department of Computer Science and Engineering, University of Washington, who obtained her Ph.D. from the Massachusetts Institute of Technology (MIT). Her research focuses on "neurobotics" (also spelled neurorobotics), or how electrical signals in the brain could translate into movement of a robotic prosthetic. It involves several fields, including computer science, biomechanics, biophysics, material science, and psychophysics. She is also the head of the non-profit YokyWorks Foundation, which creates specific devices for people with disabilities.

19 April, 2012

Quantum physics is a branch of physics that deals with quanta (discrete units of energy) as described by quantum theory.

The name quantum comes from the Latin word for "how much". This field was developed because classical (or Newtonian) physics doesn't apply to atomic particles; radiation from black bodies (a black body absorbs and then emits all radiation that reaches it) could not be explained by it, or by electromagnetic theory. In 1900, Max Planck came up with a theory that explained the radiation from observed black bodies, and it proposed that electromagnetic radiation comes in quanta.

There are several important ideas to quantum physics:

1. The Copenhagen Interpretation. Created by Niels Bohr, it states that nothing exists until it is measured.
2. The collapse of the wave function. The wave function--which was created by Erwin Schrodinger--of a particle "collapses" into one of all possibilities when observed.
3. The Heisenberg Uncertainty Principle. Invented by Werner Heisenberg, the principle explains that either the momentum or the position of a particle, but not both, can ever be determined.
4. The EPR Paradox. Named after Albert Einstein, Boris Podolsky, and Nathan Rosen, it was an attempt to dismantle the Copenhagen Interpretation; the basic idea is that if a pair of particles have opposite spin and you measure one of the two, the other particle immediately acquires the opposite spin, faster than the speed of light.
5. The infinity problem. This is a mathematical hang-up where in quantum electrodynamics (QED), if you try to solve Schrodinger's aforementioned wave function, you end up with an electron with infinite mass, energy, and charge, a clear impossibility.

But that's not all. Due to problems with the Copenhagen Interpretation, there is another, competing quantum theory. The Many Worlds Theory, presented by Hugh Everett III in 1957, proposes that there are as many universes as there are possibilities; that every time a measurement is taken, the universe splits into one where the measurement occurred, and many more where the measurement resulted with all the other probabilities. In the case of a particle with two possible states, the universe would divide twice.

Brian Greene is a professor of physics and mathematics at Columbia University who obtained a Ph.D. from Oxford University. He made a series of discoveries in superstring theory (which tries to bring together quantum theory and general relativity into a single unified theory) and topology change (the idea that the fabric of space can split). He is the author of The Elegant Universe, The Fabric of the Cosmos, The Hidden Reality, and Icarus at the Edge of Time. He was the host of the PBS NOVA programs The Elegant Universe and The Fabric of the Cosmos, both based on his books. He also co-founded the annual World Science Festival in 2008.

18 April, 2012

Particle physics (or high-energy physics) is a branch of physics that studies subatomic particles (also called fundamental or elementary particles) and the forces that act on them.

One of the main ideas in particle physics is of the Standard Model. According to the Model, there are three kinds of subatomic particles (which can have traits such as different spin, electric charge, mass, and lifetimes): quarks (up, down, charm, strange, top, and bottom), leptons (electron, muon, tau, electron neutrino, muon neutrino, and tau neutrino), and bosons. The bosons are the exchange particles of the four fundamental forces: the weak force (W and Z bosons), electromagnetic force (photons), strong force (gluons), and gravity (Higgs boson). The Higgs boson has yet to be found, so the Standard Model is currently incomplete, but there are ongoing experiments at CERN trying to find the Higgs.

(This is could be my all-time favorite video on YouTube. I mean it.)

The field heavily relies on the use of particle accelerators (atom
smashers). They are machines that accelerate matter using magnetic
fields and force particles to collide, the most famous of them
probably being the Large Hadron Collider. Data is also gathered by recording cosmic radiation.

Some questions beyond the Higgs boson and the Standard Model include dark matter, supersymmetry ((the idea that there may be "shadow particles" for all fundamental particles), and extra dimensions. There is also antimatter, which carries the opposite charge as regular matter; for example, since an electron has a negative charge, an anti-electron is a positron. Antimatter is thought to have had a role in the Big Bang, in that matter and antimatter existed evenly at the very beginning and unequal decay of antimatter left behind the matter existing today (baryogenesis).

Lisa Randall is the Frank B. Baird, Jr. Professor of Science at Harvard University and a former professor at Princeton University and the Massachusetts Institute of Technology (MIT), who earned a Ph.D. from Harvard in Theoretical Particle Physics. She was the first tenured woman in the physics department at Princeton and the first tenured female theoretical physicist at Harvard and MIT.

She is a member of the National Academy of Sciences, the American Philosophical Society, and the American Academy of Arts and Sciences, and was the recipient of a National Science Foundation Young Investigator Award, Alfred P. Sloan Foundation Research Fellowship, the Department of Energy (DOE) Outstanding Junior Investigator Award, the Premio Caterina Tomassoni e Felice Pietro Chisesi Award (University of Rome), the Klopsteg Award from the American Society of Physics Teachers, and the Julius Lilienfield Prize from the American Physical Society.

In 2007, she was listed by Time magazine as one of the 100 Most Influential People. She is the author of Warped Passages: Unraveling the Mysteries of the Universe's Hidden Dimensions and Knocking on Heaven's Door: How Physics and Scientific Thinking Illuminate the Universe and the Modern World.

Her research involves particle physics and cosmology, and her work has contributed to knowledge about the Standard Model, supersymmetry, baryogenesis, cosmological inflation, dark matter, and other spatial dimensions.

17 April, 2012

Oceanography (sometimes called oceanology) is the study of the world's oceans, including the life they support, their physical and chemical characteristics, the ocean floors, and exploration of the oceans.

The history of the field began with early explorers such as Captain James Cook, who mapped coastlines and explored the Great Barrier Reef. Another figure (though more well known for his theory of evolution) who contributed significant early research was Charles Darwin, who published a paper about coral reefs and atoll formation.

There are four branches of oceanography: physical oceanography (the temperature, density, pressure, and other properties of seawater), chemical oceanography (the composition and biogeochemical processes that affect it), marine geology (the structure and evolution of ocean basins), and marine ecology (also called biological oceanography; it is the study of ocean-dwelling plants and animals). There is also Ocean Engineering, which involves the design and manufacture of objects to be used in water. The overall field of oceanography incorporates biology, chemistry, geology, meteorology, and physics.

Information about currents, waves, ocean fronts, and variations in magnetic and gravitational fields are taken using special instruments, with recent technology such as satellites taking over for observations that were formerly made from aircraft, buoys, and ships; satellites are also capable of mapping the ocean surface, currents, waves, winds, phytoplankton levels, sea ice, rainfall, and sea surface temperature. Autonomous undersea vehicles (or AUVs) are another type of machine used that does not require people to be out on the water. Many measurements are now electronic, and probes that can test chemical and biological factors are being used and developed.

Gene Carl Feldman is an oceanographer who has been at NASA since 1985. His projects have included sea turtle conservation, the production, archival, and distribution of satellite data, SeaWiFS (Sea-viewing Wide Field-of-view Sensor, which aimed to provide information on ocean color, or its "bio-optical properties"), hydrothermal vents, exploring the Kaikoura Canyon in New Zealand, and underwater dives. He has been part of programs involving the BBC, Discovery Channel, National Geographic Society, Cousteau Society, Smithsonian, and PBS, and he created the JASON Project with Robert Ballard, another oceanographer.

Video with Gene Carl Feldman talking about the Galapagos Islands and oceanography:

16 April, 2012

Nanotechnology is the science of building objects the size of atoms and molecules, from 1-100 nanometers.

A nanometer (nm) is a billionth of a meter (10 to the power of -9) or about the length of six carbon atoms; for further comparison, the size of a red blood cell is around 7,000 nm. The word "nano" comes from the Greek word for dwarf. Richard Feynman (who won the Nobel Prize for Physics) was the first to lecture on nanotechnology in 1959, though the phrase itself was coined in 1974 by Norio Taniquichi.

Matter at the nanoscale displays unique physical, chemical, and biological traits, and nanotechnology can create materials that are stronger, more conductive, more chemically reactive, reflect more light, and have different magnetic properties. These changes are called quantum effects, and happen only at the nanoscale.

Nanotechnology has applications in a wide range of fields, such as medicine, computing, information and communications technology, the aerospace industry, materials synthesis, and imaging and printing. It has been used in sunscreens, cosmetics, clothes, eyeglasses, Tupperware products, computers, baseball bats and tennis rackets, automobiles, and batteries, to name a few. Future uses may include the engineering of building materials, drugs, artificial tissues, food, solar panels, improvement of water and air quality, and there are even experiments being done to see if an invisibility cloak could be made with nanoparticles.

It has been predicted that by 2014, $2.5 trillion worth of goods will have some form of nanotechnology, or around 15% of all global output. There is a more negative side to nanotechnology, however, since it could have negative effects on living things (humans included) and create new nano pollutants, in addition to other other unforseen dangers.

Notable Nanotechnologist:

Naomi Halas

Naomi Halas is the Stanley C. Moore Professor in Electrical and Computer Engineering, a Professor of Biomedical Engineering, Chemistry, Physics and Astronomy, and the Director of the Laboratory for Nanophotonics (which she founded) at Rice University. She has over 15 issued and pending patents and is the co-founder of Nanospectra Biosciences, Inc., a company developing photothermal cancer therapy. She is a Fellow of the Optical Society, the American Physical Society, the International Society for Optical Engineering (SPIE), the Institute for Electrical and Electronics Engineers, and the American Association for the Advancement of Science.

Her research group focuses on metallic nanoparticles and nanostructures and their optical characteristics, including light absorption and scattering and plasmon-plasmon interactions (a plasmon is the oscillation of free electrons). Projects involve diagnostic and therapeutic nanoparticles and their potential uses in cancer therapy and imaging, and light-triggered gene therapy (nanoparticles are deposited in cells, and light causes them to release DNA).

Do you worry about the potential issues that nanotechnology could bring with it? Or do you think humanity's engineering at the nanoscale is more on the positive side? Or (as with so many fields these days) both?

14 April, 2012

Microbiology is the study of microorganisms (also called microbes), including bacteria, archaea, algae, fungi, protozoa, viruses, and prions.

The field began when Antonie van Leeuwenhoek (1632-1723), a Dutch draper who ground lenses and created microscopes as a hobby, described and drew many microorganisms, which he called "animalcules". Microbiology was further developed when in 1864 Louis Pasteur disproved spontaneous generation (or abiogenesis; that living things could come from nonliving matter) and Ferdinand Cohn classified bacteria in 1872.

There are eight important characteristics of microorganisms: morphology (size, shape, and arrangement of cells), nutrition, physiology, reproduction and growth, metabolism, pathogenesis (whether the microorganism is disease-causing), antigenicity (whether the microorganisms causes antibodies to be released when introduced into an animal), and genetic characterization (the chemical composition, synthesis, and replication of genetic material).

These characteristics are studied using a range of technology. Microscopy includes light microscopy (light microscopes have magnifications up to 2000x), electron microscopy (with magnifications that enable things as small as .02 nanometers), atomic force microscopy (which can create images of any material), scanning tunneling microscopy (which generates 3D images), and immunoelectron microscopy (which uses antibodies to detect intracellular structures).

Ruth Ley is an Assistant Professor at the Department of Molecular Biology and Genetics, Cornell University. She has been awarded the National Institutes of Health (NIH) New Innovator award and the Packard Fellowship, and was a Packard Fellow, Hartwell Investigator, and Beckman Young Investigator.

She has worked on research involving the effects of fire on woodlands, nitrogen content of water due to microorganisms in soil, and bacteria in the gut of a range of animals (including humans), sequencing over 20,000 genes and comparing them with microorganisms from humans, rats, cows, and gorillas. Her current research team focuses on symbionts and the affect their mammalian hosts have on their diversity in the gut.

13 April, 2012

Lithology is the study, description, and classification of rocks. It is closely related to petrology, another branch of geology.

The field developed from geology during the late 1800s and early 1900s. Lithology is tied to many other disciplines of science including stratigraphy, tectonics, paleogeography, geochemistry, paleontology, and climatology. An important theory to lithology is lithogenesis (the formation and change in sedimentary rocks), of which there are four kinds: glacial, humid, arid, and volcanogenic-sedimentary.

Current lithological research looks into the formation, composition, and structure of sediments on both land and sea. Data are gathered by field research, laboratory work, and generalization. Field research includes detailed description of the composition and structure of rocks; laboratory work depends on analysis and experiments (such as thermal analysis, electron microscopy, and observation of optical properties of rocks); and generalization is the expression of collected data (to see an example of technology used in the display of lithology data, go HERE).

James Myers is a professor at the University of Wyoming who graduated from John Hopkins University with Ph.D. in Geology. His research involves the petrogenesis (origins) of island arcs created by magma, the petrography (lithology) of volcanic rocks, and thermal and fluid dynamics (see yesterday's post) of magma.